My ducks share their coop with my chickens with no issue. They use the same 1x1 foot tall door that our chickens use. We have a double sesat up where we have the main coop thats set up to have storage in the front, a chicken wire divider, and door, a big roosting area with food, and water, and nesting boxes behind that, and on top is a loft for more storage. Then we have a secondary outter coop with a larger roosting area, awning style metal roof, nesting boxes, main food container and a small 1/2x1 1/2 ft door leading to one of the two runs, and a person sized door on the opposite side leading to the other run.
Oure main coop (the one with storage) is buily using wooden plywood walls fortified using two by fours, then insulated with plastic inner walls. Theirs a nesting box we also added on the floor for our ducks. The outside was added using a large plastic sheet andextra fencing with the gate having plastic on it (during winter) as well. The opposite side where the smaller door is, was made from some old wood fencing. And believe it or not, the ducks and chickens preffer to sleep in the outter part of the coop I just described.
